The writer of Billy Elliot, Lee Hall, recently observed that, for younger members of the audience at his movie and its spin-off musical, coal miners are historical or mythical figures. The question now is whether, in 20 years, tiny theatre-goers will stare in wonder at the exotic figure of the postal delivery worker.

Yesterday's vote for a national postal strike – consolidating a series of localised stoppages which have left several millions of items undelivered – is shaping up to be the biggest stand-off between a traditional workforce and reforming management since Arthur Scargill took on the Thatcher government over pit closures in 1984. The outcome will decide whether Billy Hayes of the Communication Workers Union will, like Scargill, be remembered as someone who presided over the destruction of the industry he was meant to represent.

This comparison is also instructive because the two most vital decisions when planning a strike are timing and the availability of alternative labour. Scargill, notoriously, was provoked into walking out in summer, when demand for coal was at its lowest and stockpiles highest. An intriguing counter-history is what might have happened if, like the miners who brought down Edward Heath's government, he had struck in the frozen wastes of winter. In this respect, the CWU has been cannier. Late autumn and early winter is the moment of maximum inconvenience for a postal strike because of the approach of the season in which people most excitedly await the arrival of the mail.

Yet conversely Hayes seems, even more than Scargill did, to have underestimated the available alternatives to his workers. Imported European coal and rival sources of power made the NUM's stance parlous; 25 years ago but the postal workers now are understudied by rival performers in every aspect of their act.

Letters have been largely replaced by email – creating the cashflow crisis which, management says, makes changes necessary – and, while the Royal Mail had the luck that bulky packages can't yet be sent electronically, the cyber-stores are likely to have private delivery trucks purring outside the warehouse, ready to go at the moment the official vans are clamped. Amazon has already transferred its contract for the heaviest parcels to a private supplier.

It's this possibility of substitution which is crucial. The railway unions retain considerable power because silent rail tracks create commuter fury and roads, the obvious rival means of transport, are already crowded and unreliable.

Paradoxically, the presence of easy alternatives can sometimes play in the favour of workers: broadcast unions (especially at the BBC) still have heft because managers are reluctant to leave their wavelengths blank while others steal the audiences.

The bosses of Royal Mail, however, seem primed for a fight, arguing that only a new set of rules applied to fewer workers can keep the business going. There has to be some sympathy for this position. British Telecom – another UK communications giant threatened by new ways of contact – suffered huge losses in profits and employment but was at least able to offset some of the damage from mobile phones through its presence in broadband. In contrast, the postal side of the old state monopoly, unable to compete in any part of cyberspace and with a pension fund which resembles a gushing jugular, can only hope to keep its physical delivery division as efficient as possible.

The problem is that a classic stand-off, common in troubled industries, has occurred. Even those staff who accept that their trade has become a shark-infested sea simply don't trust their captains to steer the right path through it.

One comparison with the miners' strike, though, is hopeful for the posties. In 1984, it now seems clear, a political decision had been taken to rid Britain of its dependence on men bent double underground with pick-axes. In this case, there was no such hidden agenda to stamp out letters. The alternative means of communication – through the internet – happened accidentally, and the Royal Mail is an unfortunate bystander.

The unions' best hope is that the management will calculate that a Christmas of sealed letterboxes would be the business's last and agree a compromise package, deferring nemesis to another year. If that happens, then the CWU's timing will prove to have been as triumphant as the NUM's was disastrous.

The alternative – a lengthy dispute – seems to have only one possible outcome: letters becoming entirely electronic and packages delivered by private vans. Billy Hayes should perhaps exchange urgent emails with Arthur Scargill. The strong feeling is that he has just posted a suicide letter on behalf of his workers.